/*
 * Copyright 2009 The Apache Software Foundation
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hbase.client;

import org.apache.hadoop.hbase.io.HbaseObjectWritable;
import org.apache.hadoop.hbase.io.Writable;
import org.apache.hadoop.hbase.util.Bytes;

import java.io.DataOutput;
import java.io.IOException;
import java.io.DataInput;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

/**
 * Container for Actions (i.e. Get, Delete, or Put), which are grouped by
 * regionName. Intended to be used with HConnectionManager.processBatch()
 */
public final class MultiAction<R> implements Writable {

	// map of regions to lists of puts/gets/deletes for that region.
	public Map<byte[], List<Action<R>>> actions = new TreeMap<byte[], List<Action<R>>>(Bytes.BYTES_COMPARATOR);

	public MultiAction() {
	}

	/**
	 * Get the total number of Actions
	 *
	 * @return total number of Actions for all groups in this container.
	 */
	@SuppressWarnings("rawtypes")
	public int size() {
		int size = 0;
		for (List l : actions.values()) {
			size += l.size();
		}
		return size;
	}

	/**
	 * Add an Action to this container based on it's regionName. If the regionName
	 * is wrong, the initial execution will fail, but will be automatically
	 * retried after looking up the correct region.
	 *
	 * @param regionName
	 * @param a
	 */
	public void add(byte[] regionName, Action<R> a) {
		List<Action<R>> rsActions = actions.get(regionName);
		if (rsActions == null) {
			rsActions = new ArrayList<Action<R>>();
			actions.put(regionName, rsActions);
		}
		rsActions.add(a);
	}

	public Set<byte[]> getRegions() {
		return actions.keySet();
	}

	/**
	 * @return All actions from all regions in this container
	 */
	public List<Action<R>> allActions() {
		List<Action<R>> res = new ArrayList<Action<R>>();
		for (List<Action<R>> lst : actions.values()) {
			res.addAll(lst);
		}
		return res;
	}

	@SuppressWarnings("rawtypes")
	@Override
	public void write(DataOutput out) throws IOException {
		out.writeInt(actions.size());
		for (Map.Entry<byte[], List<Action<R>>> e : actions.entrySet()) {
			Bytes.writeByteArray(out, e.getKey());
			List<Action<R>> lst = e.getValue();
			out.writeInt(lst.size());
			for (Action a : lst) {
				HbaseObjectWritable.writeObject(out, a, a.getClass(), null);
			}
		}
	}

	@SuppressWarnings({ "rawtypes", "unchecked" })
	@Override
	public void readFields(DataInput in) throws IOException {
		actions.clear();
		int mapSize = in.readInt();
		for (int i = 0; i < mapSize; i++) {
			byte[] key = Bytes.readByteArray(in);
			int listSize = in.readInt();
			List<Action<R>> lst = new ArrayList<Action<R>>(listSize);
			for (int j = 0; j < listSize; j++) {
				lst.add((Action) HbaseObjectWritable.readObject(in, null));
			}
			actions.put(key, lst);
		}
	}

}
